JPWO2012073887A1 - Phosphor and light emitting device - Google Patents

Abstract

The present invention efficiently emits green fluorescence by excitation light in a wavelength range from blue light to near ultraviolet light, and has a small change in emission intensity with respect to wavelength variation of excitation light, and can be easily manufactured. Provide the body. The phosphor according to the present invention has a chemical structure represented by the following general formula (A). A (M1-a-xEuaMnx) L (Si1-bGeb) 2O7 (A) (A is one or more elements selected from Li, Na, and K, M is Mg, Ca, Sr, Ba, Zn, And one or more elements selected from Mn, L is one or more elements selected from Ga, Al, Sc, Y, La, Gd, and Lu, and a is 0.001 ≦ a ≦ 0.3. The number to be satisfied, b is a number that satisfies 0 ≦ b ≦ 0.5, and x is a number that satisfies 0 ≦ x ≦ 0.2.

Description

  The present invention relates to a phosphor and a light-emitting device including the phosphor.

  In recent years, with the improvement of the light emission efficiency of light emitting diodes (LEDs), light emitting devices using LEDs are becoming popular and expanding. In particular, a light-emitting device including an LED and a phosphor that converts the wavelength of light emitted from the LED can be highly efficient, small, thin, and power-saving, and can be arbitrarily selected depending on the application such as white color or light bulb color. It has the feature that it is possible to emit light in the colors. For this reason, this type of light-emitting device can be used for indoor and outdoor lighting fixtures, liquid crystal displays, backlight light sources for mobile phones and personal digital assistants, display devices used for indoor and outdoor advertisements, in-vehicle light sources, and the like. Expected and being developed.

  Various configurations have been proposed as a configuration of a light emitting device that emits white light. Among them, a light emitting device (for example, see Patent Document 1) including a blue LED and a yellow phosphor is most popular. In this light emitting device, it is utilized that blue and yellow are in a complementary color relationship, and a part of blue light emitted from the blue LED is converted into yellow light by a yellow phosphor, so that the light emitting device emits blue light. Pseudo white light including yellow light is emitted.

  However, although the luminous efficiency of such a light emitting device that emits pseudo white light is high, the pseudo white light contains little or no green light and red light, and thus has a problem of low color rendering. .

  As a light emitting device that emits white light, a light emitting device that includes a blue LED, a green phosphor, and a red phosphor (see, for example, Patent Document 2), and a light emitting device that includes a near ultraviolet LED, a blue phosphor, a green phosphor, and a red phosphor. An apparatus (see, for example, Patent Document 3) has also been proposed. These light emitting devices emit white light that is relatively close to natural light including blue light, green light, and red light.

  In Patent Document 2, as a green phosphor, it absorbs blue light emission, can emit a light emission spectrum having a peak at 530 to 570 nm, and extending to at least 700 nm, has a garnet structure and contains cerium. A photoluminescent phosphor is disclosed.

Patent Document 3 discloses a phosphor having a general formula Eu _s (Si, Al) _6-s (O, N) ₈ and having a beta sialon crystal structure as a green phosphor. In this general formula, s is a number from 0.011 to 0.019.

However, in the green phosphor disclosed in Patent Document 2, since the ion serving as the emission center is Ce ³⁺ , the wavelength range of excitation light is 440 to 460 nm in order to stabilize the emission intensity of the green phosphor. It will be limited to the range. For this reason, this green phosphor is effective only when used with a blue LED. For example, when used with a near-ultraviolet LED, there is a problem that the emission intensity of the green phosphor does not increase sufficiently. Furthermore, even when this green phosphor is used with a blue LED, the emission wavelength of the blue LED varies depending on the production lot of the blue LED, or the emission wavelength fluctuates due to the temperature rise of the blue LED. There is also a problem that the emission intensity of the green phosphor easily fluctuates greatly. For this reason, the luminous flux and chromaticity of white light emitted from the light emitting device are likely to fluctuate.

  The green phosphor disclosed in Patent Document 3 is manufactured through a process in which the raw material is baked at a high temperature of 1820 ° C. to 2200 ° C. in a nitrogen atmosphere. For this reason, there is a problem in that a manufacturing facility for high-temperature heating is required and the manufacturing process becomes very complicated, resulting in an increase in manufacturing cost.

Japanese Patent No. 3700502 Japanese Patent No. 4148245 Japanese Patent No. 4104013

  The present invention has been made in view of the above-mentioned reasons, and the object of the present invention is to be excited efficiently by excitation light in a wavelength range from blue light to near ultraviolet light to emit green fluorescence. An object of the present invention is to provide a phosphor that can be easily manufactured with a small change in emission intensity with respect to wavelength variation, and a light-emitting device including the phosphor.

  The phosphor according to the present invention has a chemical structure represented by the following general formula (A).

A (M _{1-a x} Eu _a Mn _x ) L (Si _1-b Ge _b ) ₂ O ₇ (A)
(A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, Y , La, Gd, and Lu, one or more elements selected from Lu, a is a number satisfying 0.001 ≦ a ≦ 0.3, b is a number satisfying 0 ≦ b ≦ 0.5, and x is 0 ≦ x It is a number satisfying ≦ 0.2.)
In the present invention, x in the general formula (A) preferably satisfies x = 0. In this case, the phosphor according to the present invention has a chemical structure represented by the following general formula (1).

A (M _1-a Eu _a ) L (Si _1-b Ge _b ) ₂ O ₇ (1)
(A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, Zn, and Mn, and L is Ga, Al, Sc. , Y, La, Gd and Lu, one or more elements selected from Lu, a is a number satisfying 0.001 ≦ a ≦ 0.3, and b is a number satisfying 0 ≦ b ≦ 0.5.
In the present invention, x in the general formula (A) preferably satisfies 0 <x ≦ 0.2.

In this invention, it is preferable that Li is contained in A in the said General formula (1).

In the present invention, it is also preferable that Na is contained in A in the general formula (A).

  In the present invention, it is also preferable that A in the general formula (A) is composed of at least two elements.

  In the present invention, it is also preferred that Ba in the general formula (A) contains Ba.

  In the present invention, it is also preferable that M in the general formula (A) is composed of at least two elements.

  In the present invention, it is also preferable that Sc in L in the general formula (A) is contained. It is also preferable that Y in L in the general formula (A) is further contained.

  The phosphor according to the present invention preferably has a composition represented by the following general formula (2).

A ¹ _1-y A ² _y Ba _1-a Eu _a ScSi ₂ O ₇ (2)
(A ¹ and A ² are elements selected from Li, Na, and K, and A ¹ and A ² are different from each other. Y is a number that satisfies 0 <y <1, and a is 0. (The number satisfies 001 ≦ a ≦ 0.3.)
The phosphor according to the present invention preferably has a composition represented by the following general formula (3).

NaBa _1-a Eu _a ScSi ₂ O ₇ (3)
(A is a number satisfying 0.001 ≦ a ≦ 0.3.)
The phosphor according to the present invention preferably has a composition represented by the following general formula (4).

NaBa _1-a Eu _a Sc _1-z Y _z Si ₂ O ₇ (4)
(Z is a number that satisfies 0 <z <1, and a is a number that satisfies 0.001 ≦ a ≦ 0.3.)
The phosphor according to the present invention preferably has a composition represented by the following general formula (5).

NaM ¹ _p M ² _q Eu _a ScSi ₂ O ₇ (5)
(M ¹ and M ² are elements selected from Mg, Ca, Sr, Ba, and Zn, and M ¹ and M ² are different from each other. A is a number that satisfies 0.001 ≦ a ≦ 0.3. P is a number that satisfies 0 <p <1, q is a number that satisfies 0 <q <1, and p, q, and a satisfy p + q + a = 1.)
The phosphor according to the present invention preferably has a composition represented by the following general formula (6).

A (M ³ _{1−a x} Eu _a Mn _x ) L (Si _1−b Ge _b ) ₂ O ₇ (6)
(A is one or more elements selected from Li, Na, and K, M ³ is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, One or more elements selected from Y, La, Gd, and Lu; a is a number satisfying 0.001 ≦ a ≦ 0.3; b is a number satisfying 0 ≦ b ≦ 0.5; It is a number satisfying 01 ≦ x ≦ 0.1.)
A light-emitting device according to the present invention includes a light-emitting element that emits light having a main light emission peak in a range of 350 nm to 470 nm, and a wavelength conversion member that absorbs light emitted from the light-emitting element and emits light, and the wavelength conversion member Comprises the phosphor.

  The phosphor according to the present invention is efficiently excited by excitation light in a wavelength range from blue light to near ultraviolet light to emit green fluorescence, and the change in emission intensity with respect to wavelength variation of the excitation light is small, and easily. It can be manufactured.

  The light emitting device according to the present invention exhibits high luminous efficiency and wavelength conversion efficiency by including the phosphor.

It is a partially broken disassembled perspective view which shows the light-emitting device in one Embodiment of this invention. It is sectional drawing of the said light-emitting device. It is a schematic diagram which shows the internal structure of the wavelength conversion member with which the said issuing apparatus is provided. It is a graph which shows the fluorescence emission spectrum of the fluorescent substance which concerns on Example 1 of this invention. It is a graph which shows the excitation spectrum of the fluorescent substance which concerns on Example 1 of this invention. For particles of a phosphor obtained in Example 7-11, the diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. For particles of a phosphor obtained in Example 12 and 13, the diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. For particles of a phosphor obtained in Example 14, the diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. For particles of a phosphor obtained in Example 15-18, a diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. For particles of a phosphor obtained in Example 19 to 22, the diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. For particles of a phosphor obtained in Example 23-25, a diffraction intensity curve obtained by powder X-ray diffraction measurement, as well as NaBaScSi ₂ O _7, a graph showing the diffraction intensity curve obtained by simulation. It is a graph which shows the measurement result of the excitation spectrum and emission spectrum about the particle | grains of the fluorescent substance obtained in Example 12. FIG. It is a graph which shows the emitted light intensity in the emission peak wavelength in the emission spectrum about Examples 7-11. It is a graph which shows the emitted light intensity in the emission peak wavelength in the emission spectrum about Examples 15-18. It is a graph which shows the emitted light intensity in the emission peak wavelength in the emission spectrum about Examples 19-22. It is a graph which shows the emitted light intensity in the emission peak wavelength in the emission spectrum about Examples 23-25. It is a graph which shows the measurement result of an excitation spectrum and an emission spectrum about the particle | grains of the fluorescent substance obtained in Examples 7-11. It is a graph which shows the measurement result of the excitation spectrum and emission spectrum about the particle | grains of the fluorescent substance obtained in Examples 28-31. It is a graph which shows the measurement result of the excitation spectrum and emission spectrum about the particle | grains of the fluorescent substance obtained in Examples 32-35.

[Phosphor]
The phosphor according to the present embodiment has a chemical structure represented by the following general formula (A).

A (M _{1-a x} Eu _a Mn _x ) L (Si _1-b Ge _b ) ₂ O ₇ (A)
A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, Y, One or more elements selected from La, Gd, and Lu, a is a number that satisfies 0.001 ≦ a ≦ 0.3, b is a number that satisfies 0 ≦ b ≦ 0.5, and x is 0 ≦ x ≦ It is a number satisfying 0.2.

  The compositions represented by the general formulas (1) to (6) to be described later are all subordinate concepts of the composition represented by the general formula (A), and are therefore represented by the general formulas (1) to (6). The phosphors having the composition are all included in the phosphor having the chemical structure represented by the general formula (A).

In the general formula (A), the composition ratio (molar ratio) of A: (M _{1-a x} Eu _a Mn _x ): L: (Si _1-b Ge _b ): O is 1: 1: 1: Although it is 2: 7, there may naturally be a case where the composition ratio in the phosphor does not exactly follow this due to partial defects in the crystal structure, contamination of impurities, and other reasons. However, even if the composition ratio of the phosphor is not completely coincident with 1: 1: 1: 2: 7, the composition ratio is substantially 1: 1: 1: 2: 7 based on common general technical knowledge. If considered, this phosphor is within the scope of the present invention.

  In the general formula (A), when x = 0, the phosphor according to the present embodiment has a chemical structure represented by the following general formula (1).

A (M _1-a Eu _a ) L (Si _1-b Ge _b ) ₂ O ₇ (1)
A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, Y, La, One or more elements selected from Gd and Lu, a is a number satisfying 0.001 ≦ a ≦ 0.3, and b is a number satisfying 0 ≦ b ≦ 0.5.

This phosphor is a silicate-based phosphor activated with divalent europium ions. In the phosphor crystal having such a composition, the ion serving as the emission center is a divalent europium ion Eu ²⁺ . This Eu ²⁺ is dissolved in the crystal by substituting this M for a part of the site occupied by the divalent ions of the metal element M in the crystal. By having such a crystal structure, the phosphor is efficiently excited by absorbing excitation light in a wavelength range from near ultraviolet light to blue light, particularly in a wavelength range of 350 to 470 nm, and is more than the wavelength of the excitation light. Efficiently emits long-wavelength fluorescence.

  In general formula (A) and general formula (1), as described above, A is one or more alkali metal elements selected from Li, Na, and K. A may be composed of only one element of Li, Na, and K, or may be composed of two or more elements. When A consists of two or more elements, the ratio of each of the two or more elements in A may be an appropriate ratio.

In particular, it is preferable that A in the general formula (A) and the general formula (1) necessarily contains Li. That is, it is preferable that A consists of Li or A consists of Li and at least one of Na and K. In this case, Eu ²⁺ ions are easily selectively replaced with the divalent ions of the metal element M at the sites occupied by the divalent ions of the metal element M in the crystal. Therefore, the luminous efficiency of the phosphor is particularly high. Become. In particular, the proportion of Li in A is preferably 1 to 100 mol%.

  It is also preferable that A in the general formula (A) and the general formula (1) necessarily contains Na. That is, it is preferable that A consists of Na alone, or A consists of Na and at least one of Li and K. In this case, the crystallinity of the phosphor is further improved.

  It is also preferred that A in general formula (A) and general formula (1) consists of at least two elements. That is, it is preferable that A consists of at least two of Na, Li and K. In this case, the emission peak wavelength can be adjusted within a range of several nm by adjusting the composition ratio.

  In the general formula (A) and the general formula (1), M is one or more metal elements selected from Mg, Ca, Sr, Ba, and Zn as described above. M may be composed of only one element of Mg, Ca, Sr, Ba, or Zn, or may be composed of two or more elements. When M is composed of two or more elements, the ratio of each of the two or more elements in M may be an appropriate ratio. In the crystal, the metal element M becomes a divalent ion as described above.

  In particular, it is preferable that M in the general formula (A) and the general formula (1) necessarily includes Ba. That is, it is preferable that M is composed only of Ba, or that M is composed of Ba and at least one of Mg, Ca, Sr, and Zn. In this case, the crystallinity of the phosphor is further improved.

  It is also preferable that M in the general formula (A) and the general formula (1) is composed of at least two elements. That is, it is preferable that M consists of at least two of Mg, Ca, Sr, Ba, and Zn. In this case, the emission peak wavelength can be adjusted within a range of several nm by adjusting the composition ratio.

  In the general formula (A) and the general formula (1), a is a number indicating the molar ratio of Eu to the metal element M, and is a number satisfying 0.001 ≦ a ≦ 0.3 as described above. When the value of a is 0.001 or more, the concentration of divalent europium ions in the crystal is sufficiently high, and when the value of a is 0.3 or less, concentration quenching is suppressed, This sufficiently increases the emission intensity of the phosphor. In order to further reduce concentration quenching, the value of a is particularly preferably 0.2 or less. That is, when a is a number satisfying 0.001 ≦ a ≦ 0.2, the emission intensity of the phosphor is particularly high. Furthermore, a is preferably a number satisfying 0.01 ≦ a ≦ 0.1.

  In the general formula (A) and the general formula (1), L is one or more metal elements selected from Ga, Al, Sc, Y, La, Gd, and Lu as described above. L may be composed of only one element of Ga, Al, Sc, Y, La, Gd, and Lu, or may be composed of two or more elements. When L consists of two or more elements, the ratio of each of the two or more elements in L may be an appropriate ratio. In the crystal, the metal element L becomes a trivalent ion.

  In particular, it is preferable that L in the general formula (A) and the general formula (1) necessarily includes Sc. That is, it is preferable that L consists only of Sc, or that L consists of Sc and at least one of Ga, Al, Y, La, Gd, and Lu. In this case, the crystallinity of the phosphor is further improved.

  In particular, it is preferable that L in the general formula (A) and the general formula (1) includes Sc and further includes Y. That is, it is preferable that L is composed only of Sc and Y, or L is composed of Sc and Y, and at least one of Ga, Al, La, Gd, and Lu. In this case, the emission peak wavelength can be adjusted within a range of several nm by adjusting the composition ratio.

  As shown in the general formula (A) and the general formula (1), part of Si in the crystal may be substituted with Ge. In general formula (A) and general formula (1), b is a number indicating the molar ratio (substitution ratio) of Ge to Si, and is a number satisfying 0 ≦ b ≦ 0.5 as described above. When the value of b is 0.5 or less, the high luminous efficiency of the phosphor is maintained.

  An example of a method for manufacturing a phosphor will be described. First, a mixture is prepared by blending multiple types of raw materials. The blending ratio of the raw materials is adjusted so that the metal element in the mixture matches the composition represented by the general formula (A) or the general formula (1).

For example, when A in the general formula (1) is Na, M is Ba, L is Sc, and b = 0, that is, a phosphor having a composition of NaBaScSi ₂ O ₇ : Eu ²⁺ is produced, For example, powders of Na ₂ CO ₃ , BaCO ₃ , Eu ₂ O ₃ , Sc ₂ O ₃ , and SiO ₂ are used. The mixing ratio of these raw materials is adjusted so that the molar ratio of Na, Ba, Sc, Si and Eu in the mixture matches the composition of the phosphor.

  Next, a container made of a material such as alumina or quartz is prepared, and the mixture is placed in the container. Subsequently, the mixture in the container is fired at a temperature of 1000 to 1300 ° C. in a non-oxidizing gas atmosphere. The non-oxidizing gas atmosphere is preferably a weak reducing gas atmosphere such as a hydrogen / nitrogen mixed gas atmosphere. Thus, before a mixture is baked, a mixture may be pre-baked in air | atmosphere previously, and the crystallinity of fluorescent substance becomes especially high in this case. When the mixture is temporarily fired, the firing temperature at the time of temporary firing is preferably equal to or lower than the firing temperature at the time of main firing (when firing in the non-oxidizing gas atmosphere following the temporary firing).

  Thus, the phosphor according to the present embodiment can be manufactured through a process in which the raw material is baked at a relatively low temperature of 1000 to 1300 ° C. in a non-oxidizing gas atmosphere. This eliminates the need for manufacturing equipment for high-temperature heating and simplifies the manufacturing process. Therefore, the phosphor according to the present embodiment can be easily manufactured.

  Next, the sintered body obtained by sintering the mixture is crushed and pulverized, and then washed with water or acid to remove unnecessary components. Thereby, a phosphor powder having a target composition is obtained.

The phosphor according to the present embodiment can be applied to a light emitting device including a light emitting element such as an LED. The light-emitting element is not particularly limited, but is preferably a light-emitting element that emits light having a main light emission peak in the range of 350 nm to 470 nm. A nitride semiconductor LED is mentioned as a preferable example of such a light emitting element. The nitride semiconductor in the nitride semiconductor LED is a compound semiconductor having a composition of, for example, In _x Ga _y Al _z N (0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1, x + y + z = 1). Examples of important specific examples of the nitride semiconductor include AlN, GaN, AlGaN, InGaN, and the like.

  When the nitride semiconductor LED emits violet light or near-ultraviolet light, the emission wavelength of the nitride semiconductor LED is 410 nm or less, but when the emission wavelength is in the range of 365 nm to 410 nm, the nitride semiconductor LED is particularly efficient. Emits light. When the nitride semiconductor LED emits blue light, the nitride semiconductor LED emits light with particularly high efficiency when the emission wavelength of the nitride semiconductor LED is in the range of 420 nm to 480 nm. Therefore, when the phosphor according to the present embodiment is applied to a light-emitting device including such a nitride semiconductor LED, the light-emitting efficiency of the light-emitting device is particularly high.

  More specific aspects of the phosphor according to this embodiment will be described.

  In the first embodiment, the phosphor has a composition represented by the following formula (2).

A ¹ _1-y A ² _y Ba _1-a Eu _a ScSi ₂ O ₇ (2)
In this first embodiment, A ¹ and A ² are elements selected from Li, Na, and K, and A ¹ and A ² are different from each other. A ¹ is particularly Na. A ² is in particular K or Li.

In the formula (2), y is a value that indicates the molar ratio of ^{A 2} to the sum of ^{A 1} and ^{A 2.} This y may be any number that satisfies 0 <y <1. When A ¹ is Na and A ² is K, y preferably satisfies 0.05 ≦ y ≦ 0.7. When A ¹ is Na and A ² is Li, y preferably satisfies 0.3 ≦ y ≦ 0.7.

  In the second embodiment, the phosphor has a composition represented by the following formula (3).

NaBa _1-a Eu _a ScSi ₂ O ₇ (3)
In the third embodiment, the phosphor has a composition represented by the following formula (4).

NaBa _1-a Eu _a Sc _1-z Y _z Si ₂ O ₇ (4)
In the formula (4), z represents the molar ratio of Y to the total of Sc and Y. This z may be any number that satisfies 0 <z <1. In particular, z preferably satisfies 0.05 ≦ z ≦ 0.5, and z preferably satisfies 0.05 <z <0.3.

  In the fourth aspect, the phosphor has a composition represented by the following formula (5).

NaM ¹ _p M ² _q Eu _a ScSi ₂ O ₇ (5)
In the fourth embodiment, M ¹ and M ² are elements selected from Mg, Ca, Sr, Ba, and Zn, and M ¹ and M ² are different from each other. M ¹ is particularly Ba. M ² is particularly Sr or Ca.

In the formula (5), p is a value that indicates the molar ratio of ^{M 1} to the total of ^M 1, ^{M 2,} and Eu, q denotes a molar ratio of ^{M 2} to the sum of ^M 1, ^{M 2,} and Eu Value. p satisfies 0 <p <1, q satisfies 0 <q <1, and p, q, and a satisfy p + q + a = 1. When M ¹ is Ba and M ² is Sr, q preferably satisfies 0.1 ≦ q ≦ 0.3. When M ¹ is Ba and M ² is Ca, q preferably satisfies 0 <q <0.1.

  In the fifth aspect, the phosphor has a composition of 0 <x ≦ 0.2 in the general formula (A). In this case, the phosphor is represented by the following general formula (6), and x has a composition satisfying 0 <x ≦ 0.2.

A (M _{1-a x} Eu _a Mn _x ) L (Si _1-b Ge _b ) ₂ O ₇ (6)
In this fifth embodiment, A is one or more elements selected from Li, Na, and K, and M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn. , L is one or more elements selected from Ga, Al, Sc, Y, La, Gd, and Lu.

  In formula (6), x is a value indicating the molar ratio of Mn to the sum of M, Eu, and Mn. x is more preferably 0.01 ≦ x ≦ 0.2, more preferably 0.01 ≦ x ≦ 0.1, and particularly preferably 0.01 ≦ x ≦ 0.07. preferable.

  In the first to fifth aspects, the phosphor is excited by efficiently absorbing excitation light in the wavelength range from near ultraviolet light to blue light, particularly in the wavelength range of 350 to 470 nm. Efficiently emits long-wavelength fluorescence. The emission spectrum of the phosphor in these embodiments has a strong emission peak in the green range, and the emission color of the phosphor is green.

  Furthermore, in the fifth aspect, the emission spectrum of the phosphor also has an emission peak in the red region. This is considered to be because Mn is used as a coactivator. The intensity of the emission peak in the red region is small compared to the emission peak in the green region. Thus, in the fifth aspect, since the main emission peak appears in the red region, the emission color of the phosphor becomes green, and since a relatively small emission peak also appears in the red region, the color rendering of the light emitting device including this phosphor Especially improved.

[Light emitting device]
The light emitting device according to this embodiment will be described. As shown in FIGS. 1 and 2, the light emitting device 1 includes an LED chip 10 that is a light emitting element, a mounting substrate 20, an optical member 60, a sealing portion 50, and a wavelength conversion member (color conversion member) 70. As will be described later, the wavelength conversion member (color conversion member) 70 includes phosphor particles formed from the phosphor according to the present embodiment.

  The LED chip 10 is mounted on the mounting substrate 20. The shape of the mounting substrate 20 is a rectangular plate shape in plan view. A pair of conductor patterns 23 for supplying power to the LED chip 10 are formed on the first surface facing the thickness direction of the mounting substrate 20, and the LED chip 10 is further mounted on the first surface. The LED chip 10 and the conductor pattern 23 are electrically connected by a bonding wire 14. The optical member 60 is a dome-shaped member, and is fixed on the first surface of the mounting substrate 20. The LED chip 10 is accommodated between the optical member 60 and the mounting substrate 20. The optical member 60 has a function of controlling the orientation of light emitted from the LED chip 10. The sealing part 50 is formed from a translucent sealing material. The sealing portion 50 is filled in a space surrounded by the optical member 60 and the mounting substrate 20. The sealing portion 50 seals the LED chip 10 and a plurality of (in this embodiment, two) bonding wires 14. The wavelength conversion member 70 is formed in a dome shape so as to surround the optical member 60. When the LED chip 10 emits light, the phosphor particles 71 in the wavelength conversion member 70 are excited by the light emitted from the LED chip 10 (excitation light), and fluorescent light having a longer wavelength than the excitation light (the emission color of the LED chip 10 and Emits converted light consisting of light of different colors. Between the optical member 60 and the wavelength conversion member 70, a gap 80 in which a gas such as air is enriched is interposed. On the first surface of the mounting substrate 20, an annular weir 27 that surrounds the outer periphery of the optical member 60 is formed. The dam portion 27 is formed so as to protrude from the first surface. Therefore, when the optical member 60 is fixed to the mounting substrate 20, even if the sealing material overflows from the space surrounded by the optical member 60 and the mounting substrate 20, the sealing material is blocked by the dam portion 27. I can be dammed up.

  The main light emission peak of the LED chip 10 is preferably in the range of 350 nm to 470 nm. Examples of such an LED chip 10 include a GaN-based blue LED chip that emits blue light and a near-ultraviolet LED chip that emits near-ultraviolet light.

  In a GaN blue LED chip, an n-type SiC substrate having a lattice constant or crystal structure closer to that of GaN than a sapphire substrate and having conductivity is used as a crystal growth substrate. On the SiC substrate, for example, a light-emitting portion having a double hetero structure is formed. The light emitting portion is formed by, for example, an epitaxial growth method (for example, MOVPE method) using a GaN-based compound semiconductor material or the like as a raw material. The LED chip 10 includes a cathode electrode on the surface facing the first surface of the mounting substrate 20 and an anode electrode on the opposite surface. The cathode electrode and the anode electrode are constituted by, for example, a laminated film of a Ni film and an Au film. The material for the cathode electrode and the anode electrode is not particularly limited, and may be any material as long as good ohmic characteristics can be obtained. For example, Al may be used.

  The structure of the LED chip 10 is not limited to the above structure. For example, after a light emitting part or the like is formed by epitaxial growth on a crystal growth substrate, a support substrate such as an Si substrate that supports the light emitting part is fixed to the light emitting part, and then the crystal growth substrate is removed. The LED chip 10 may be formed.

  The mounting board 20 includes a rectangular heat transfer plate 21 and a wiring board 22. The heat transfer plate 21 is formed from a heat conductive material. The LED chip 10 is mounted on the heat transfer plate 21. The wiring board 22 is, for example, a rectangular flexible printed wiring board. The wiring board 22 is fixed on the heat transfer plate 21 via, for example, a polyolefin-based fixing sheet 29. A rectangular window hole 24 that exposes the mounting position of the LED chip 10 on the heat transfer plate 21 is formed at the center of the wiring board 22. Inside this window hole 24, the LED chip 10 is mounted on the heat transfer plate 21 via a submount member 30 described later. Therefore, the heat generated in the LED chip 10 is conducted to the submount member 30 and the heat transfer plate 21 without passing through the wiring board 22.

  The wiring substrate 22 includes an insulating base material 221 made of a polyimide film and a pair of conductor patterns 23 for supplying power to the LED chip 10 formed on the insulating base material 221. Furthermore, the wiring board 22 includes a protective layer 26 that covers each conductor pattern 23 and covers a portion on the insulating base material 221 where the conductor pattern 23 is not formed. The protective layer 26 is formed of, for example, a white resist (resin) having light reflectivity. In this case, even if light is radiated from the LED chip 10 toward the wiring substrate 22, the light is reflected by the protective layer 26, thereby suppressing light absorption in the wiring substrate 22. Thereby, the light extraction efficiency from the LED chip 10 to the outside is improved, and the light output of the light emitting device is improved. Each conductor pattern 23 is formed in an outer peripheral shape slightly smaller than half of the outer peripheral shape of the insulating base material 221. The insulating base material 221 may be formed of an FR4 substrate, an FR5 substrate, a paper phenol resin substrate, or the like.

  Each conductor pattern 23 includes two terminal portions 231 each having a rectangular shape in plan view. The terminal portion 231 is located in the vicinity of the window hole 24 of the wiring board 22, and the bonding wire 14 is connected to the terminal portion 231. Each conductor pattern 23 further includes one external connection electrode portion 232 having a circular shape in plan view. The external connection electrode portion 232 is located near the outer periphery of the wiring board 22. The conductor pattern 23 is composed of a laminated film of a Cu film, a Ni film, and an Au film, for example.

  The protective layer 26 is patterned so that each conductor pattern 23 is partially exposed from the protective layer 26. In the vicinity of the window hole 24 of the wiring board 22, the terminal portion 231 in each conductor pattern 23 is exposed from the protective layer 26. Further, the external connection electrode portions 232 in each conductor pattern 23 are exposed from the protective layer 26 near the outer periphery of the wiring board 22.

  The LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30 as described above. The submount member 30 relieves stress acting on the LED chip 10 due to a difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21. The submount member 30 is formed in a rectangular plate shape having a size larger than the chip size of the LED chip 10.

  The submount member 30 has not only a function of relieving the stress but also a heat conduction function of conducting heat generated in the LED chip 10 in a wider range than the chip size of the LED chip 10 in the heat transfer plate 21. Yes. In the light emitting device 1 according to the present embodiment, the LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30, so that the heat generated by the LED chip 10 passes through the submount member 30 and the heat transfer plate 21. In addition, the heat acting on the LED chip 10 due to the difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21 is relieved.

  The submount member 30 is made of, for example, AlN having a relatively high thermal conductivity and an insulating property.

  The cathode electrode of the LED chip 10 is superposed on the submount member 30, and the cathode electrode is bonded with an electrode pattern (not shown) connected to the cathode electrode and a metal fine wire (for example, a gold fine wire, an aluminum fine wire, etc.). It is electrically connected to one of the two conductor patterns 23 through the wire 14. The LED chip 10 is electrically connected through a bonding wire 14 to a conductor pattern 23 that is not connected to the cathode electrode.

  For joining the LED chip 10 and the submount member 30, for example, solder such as SnPb, AuSn, SnAgCu, silver paste, or the like is used. It is particularly preferable to use lead-free solder such as AuSn or SnAgCu. When the submount member 30 is made of Cu and AuSn is used for bonding the LED chip 10 and the submount member 30, Au or Ag is previously formed on the surfaces of the submount member 30 and the LED chip 10 to be bonded to each other. It is preferable to perform a pretreatment for forming a metal layer made of For joining the submount member 30 and the heat transfer plate 21, for example, lead-free solder such as AuSn or SnAgCu is preferably used. When AuSn is used for joining the submount member 30 and the heat transfer plate 21, a pretreatment for forming a metal layer made of Au or Ag in advance on the surface of the heat transfer plate 21 to be joined with the submount member 30. Is preferably applied.

  The material of the submount member 30 is not limited to AlN, and any material may be used as long as the linear expansion coefficient is relatively close to 6H—SiC, which is the material for the crystal growth substrate, and the thermal conductivity is relatively high. For example, composite SiC, Si, Cu, CuW, or the like may be employed as the material of the submount member 30. Since the submount member 30 has the above-described heat conduction function, the area of the surface of the heat transfer plate 21 facing the LED chip 10 is the area of the surface of the LED chip 10 facing the heat transfer plate 21. It is desirable that it be sufficiently large.

  In the light emitting device 1 according to this embodiment, the heat transfer is larger than the dimension from the surface on the LED chip 10 side facing the thickness direction of the heat transfer plate 21 to the surface on the LED chip 10 side facing the thickness direction of the protective layer 26. The dimension from the surface of the plate 21 to the surface on the LED chip 10 side facing the thickness direction of the submount member 30 is larger. The thickness dimension of the submount member 30 is set so as to have such a positional relationship. For this reason, the light emitted from the LED chip 10 is suppressed from being absorbed by the wiring board 22 through the inside of the window hole 24 of the wiring board 22. Thereby, the light extraction efficiency from the LED chip 10 to the outside is further improved, and the light output of the light emitting device is further improved.

  Note that a reflective film that reflects light emitted from the LED chip 10 is formed around the position where the LED chip 10 is disposed on the surface of the submount member 30 facing the thickness direction of the LED chip 10. Good. In this case, the light emitted from the LED chip 10 is prevented from being absorbed by the submount member 30. Thereby, the light extraction efficiency from the LED chip 10 to the outside is further improved, and the light output of the light emitting device is further improved. The reflective film is composed of, for example, a laminated film of a Ni film and an Ag film.

  A silicone resin is mentioned as a sealing material which is a material for forming the above-mentioned sealing part 50. For example, an acrylic resin, glass, or the like may be used instead of the silicone resin.

  The optical member 60 is formed from a light transmissive material (eg, silicone resin, glass, etc.). In particular, when the optical member 60 is formed of a silicone resin, a difference in refractive index and a difference in linear expansion coefficient between the optical member 60 and the sealing portion 50 can be reduced.

  The light emission surface 602 (surface facing the side opposite to the LED chip 10) of the optical member 60 is light emitted from the light incident surface 601 (surface facing the LED chip 10 side) into the optical member 60. A convex curved surface is formed so as not to be totally reflected at the boundary between the surface 602 and the gap 80. The optical member 60 is disposed so that the optical axis of the LED chip 10 coincides. Therefore, the light emitted from the LED chip 10 and incident on the light incident surface 601 of the optical member 60 can easily reach the wavelength conversion member 70 without being totally reflected at the boundary between the light emitting surface 602 and the gap layer 80. The total luminous flux emitted from the light emitting device increases. The optical member 60 is formed to have a uniform thickness along the normal direction regardless of the position.

  The wavelength conversion member 70 has a light incident surface 701 (a surface facing the LED chip 10) formed in a shape along the light emitting surface 602 of the optical member 60. Therefore, regardless of the position of the light emitting surface 602 of the optical member 60, the distance between the light emitting surface 602 of the optical member 60 and the wavelength conversion member 70 in the normal direction is a substantially constant value. The wavelength conversion member 70 is formed so that the thickness along the normal direction is uniform regardless of the position. The wavelength conversion member 70 is fixed to the mounting substrate 20 with, for example, an adhesive (for example, silicone resin, epoxy resin).

  Light emitted from the LED chip 10 enters the wavelength conversion member 70 from the light incident surface 701, and goes out of the wavelength conversion member 70 through the light emission surface (surface opposite to the LED chip 10) 702 of the wavelength conversion member 70. Emitted. When light passes through the wavelength conversion member 70, a part of this light is wavelength-converted by the phosphor particles in the wavelength conversion member 70. Thereby, light of a color corresponding to the combination of the light emitted from the LED chip 10 and the type of phosphor particles in the wavelength conversion member 70 is emitted from the light emitting device 1.

  As shown in FIG. 3, the wavelength conversion member 70 includes a translucent medium 72 and a plurality of phosphor particles 71 dispersed in the translucent medium 72. At least a part of the phosphor particles 71 is formed from the phosphor according to the present embodiment.

  The wavelength conversion member 70 contains phosphor particles other than the phosphor particles formed from the phosphor according to the present embodiment as the phosphor particles 71 together with the phosphor particles formed from the phosphor according to the present embodiment. May be.

In the case where the light emitting device 1 emits white light and the LED chip 10 in the light emitting device 1 is a blue LED chip that emits blue light, for example, the wavelength conversion member 70 is used as the phosphor particle 71 and the fluorescence according to the present embodiment. It contains red phosphor particles together with green phosphor particles formed from the body. In this case, the blue light emitted from the LED chip 10 without wavelength conversion and the light converted in wavelength by the red phosphor particles and the green phosphor particles in the wavelength conversion member 70 are emitted from the wavelength conversion member 70. The Thereby, white light is emitted from the light emitting device 1. In this case, as the phosphor constituting the red phosphor particles, fluorescence having a composition such as (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ²⁺ , CaS: Eu ^2+. The body is mentioned. Other green phosphor particles may be used in combination with the green phosphor particles formed from the phosphor according to the present embodiment. In this case, as the phosphor constituting the green phosphor particles formed from the phosphor other than the phosphor according to the present embodiment, (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Y ₃ Al ₅ O ₁₂ : Ce A phosphor having a composition such as ³⁺ , (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : Eu ²⁺ , (Ca, Mg) ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Ce ³⁺ Can be mentioned. The method of selecting the phosphor particles 71 for emitting white light from the light emitting device 1 is not limited to the above example. For example, the wavelength conversion member 70 may contain a green phosphor formed from the phosphor according to the present embodiment, yellow phosphor particles, and orange phosphor particles.

When the light emitting device 1 emits white light and the LED chip 10 in the light emitting device 1 is an ultraviolet LED chip that emits ultraviolet light, the wavelength conversion member 70 is used as the phosphor particle 71, for example, according to the present embodiment. Along with the green phosphor particles formed from the phosphor, red phosphor particles and blue phosphor particles are contained. As phosphors constituting the red phosphor particles in this case, La ₂ O ₂ S: Eu ³⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ^2+, etc. A phosphor having a composition may be mentioned. Examples of the phosphor constituting the blue phosphor particles include BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , (Sr, Ca, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , and Sr ₃ MgSi ₂ O ₈ : Eu ²⁺ . A phosphor having a composition may be mentioned. Other green phosphor particles may be used in combination with the green phosphor particles formed from the phosphor according to the present embodiment. In this case, as phosphors constituting the green phosphor particles formed from phosphors other than the phosphor according to the present embodiment, (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Examples include phosphors having a composition such as Mn ²⁺ , (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : Eu ²⁺ .

  The particle diameter of the phosphor particles 71 is not particularly limited, but the larger the average particle diameter of the phosphor particles 71, the smaller the defect density in the phosphor particles 71, the less energy loss during light emission, and the light emission efficiency. Get higher. For this reason, from the viewpoint of improving luminous efficiency, the average particle diameter of the phosphor particles 71 is preferably 1 μm or more, and more preferably 5 μm or more. This average particle diameter is a value measured by a laser diffraction / scattering particle size distribution measuring apparatus.

  The phosphor particles 71 may be subjected to an appropriate surface treatment such as coating in order to suppress reflection of excitation light and fluorescence at the interface between the phosphor particles 71 and the translucent medium 72.

  The refractive index of the translucent medium 72 is preferably close to the refractive index of the phosphor particles 71, but is not limited thereto. Examples of the material of the translucent medium 72 include a silicon compound having a siloxane bond and glass. Since these materials are excellent in heat resistance and light resistance (durability against light having a short wavelength such as blue to ultraviolet), the light is transmitted by light in a wavelength range from blue light to ultraviolet light which is excitation light of the phosphor particles 71. Deterioration of the medium 72 is suppressed. Examples of silicon compounds include composites formed by crosslinking a silicone resin, a hydrolyzed condensate of organosiloxane, a condensate of organosiloxane, etc. by a known polymerization method (addition polymerization such as hydrosilylation, radical polymerization, etc.). Resin. As the translucent medium 72, for example, an acrylic resin or an organic / inorganic hybrid material formed by mixing and bonding an organic component and an inorganic component at the nm level or molecular level may be employed.

  The content of the phosphor particles 71 in the wavelength conversion member 70 takes into consideration the types of the phosphor particles 71 and the translucent medium 72, the dimensions of the wavelength conversion member 70, the wavelength conversion capability required for the wavelength conversion member 70, and the like. For example, it is in the range of 5% by mass to 30% by mass.

  When the wavelength conversion member 70 is irradiated with the excitation light of the phosphor particles 71, the phosphor particles 71 absorb the excitation light and emit fluorescence having a wavelength longer than that of the excitation light. Thereby, when light passes through the wavelength conversion member 70, the wavelength of this light is converted by the phosphor particles 71.

[Example 1]
In the general formula (1), a phosphor (NaBaScSi ₂ O7: Eu ²⁺ ) having a composition in which A is Na, M is Ba, L is Sc, a is 0.01, and b is 0 is synthesized as follows. did.

First, each powder of Na ₂ CO ₃ , BaCO ₃ , Eu ₂ O ₃ , Sc ₂ O ₃ , and SiO ₂ was weighed to obtain 1.0: 1.98: 0.01: 1.0: 4.0. The mixed powders were obtained by blending at a molar ratio of 2 and mixing them with a ball mill.

  This mixed powder was put into an alumina crucible and pre-baked by heating at 1100 ° C. for 12 hours in the air. By pulverizing the sintered body formed by this preliminary firing, the powder obtained thereby is put in an alumina crucible and heated at 1110 ° C. for 12 hours in a hydrogen / argon mixed gas atmosphere of 5% hydrogen concentration. This was fired. The sintered body formed by the main firing was pulverized to obtain phosphor particles.

[Examples 2 to 6]
In Example 1, phosphors having the compositions shown in Table 1 were produced by changing the raw material composition for producing the phosphors. As raw materials not used in Example 1, Li ₂ CO ₃ as a Li compound, SrCO _{3 as} a Sr compound, Y ₂ O ₃ as a Y compound, and GeO ₂ as a Ge compound were used.

[Evaluation]
An emission spectrum of fluorescence emitted from the phosphors obtained in Examples 1 to 6 was measured. As a measuring apparatus, a spectrofluorometer FP-6500 manufactured by JASCO Corporation was used, and the wavelength of excitation light applied to the phosphor was 450 nm. As a result, the peak wavelengths of the emission spectra of the phosphors obtained in Examples 1 to 6 were values shown in Table 1, and these emission spectra were broad spectra centered on the peak wavelength. The color of the fluorescence emitted from these phosphors was green. FIG. 4 shows the emission spectrum of the phosphor obtained in Example 1.

  Table 1 also shows the emission intensity of the fluorescence emitted from the phosphors obtained in Examples 1 to 6. This emission intensity is the intensity of the peak wavelength of the emission spectrum, and is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 1 to 100.

  The excitation spectra of the phosphors obtained in Examples 1 to 6 were also measured simultaneously using the above apparatus. The monitor wavelength was the peak wavelength in the emission spectrum. As a result, the waveform of the excitation spectrum of these phosphors is relatively flat from the near ultraviolet region to the blue region, and therefore emits light even when the wavelength of the excitation light varies in the near ultraviolet region to the blue region. It was confirmed that the intensity fluctuation was small. FIG. 5 shows the excitation spectrum of the phosphor obtained in Example 1.

[Examples 7 to 35]
Li ₂ CO ₃ powder as a raw material containing Li, Na ₂ CO ₃ powder as a raw material containing Na, K ₂ CO ₃ powder as a raw material containing K, BaCO ₃ powder as a raw material containing Ba, and a raw material containing Ca as a CaCO _3, a SrCO ₃ powder as a raw material containing Sr, a MnCO ₃ powder as raw material containing Mn, the _Eu 2 _{O 3} powder as a raw material containing Eu, and _Sc 2 _{O 3} as a raw material containing Sc, and Y Y ₂ O ₃ powder was prepared as a raw material containing, and SiO ₂ powder was prepared as a raw material containing Si, respectively.

  These raw materials were blended and mixed to prepare a mixture. At this time, in Examples 7 to 11, the raw materials were blended so that the molar ratio of Na, Ba, Eu, Sc, and Si was 1: (1-a): a: 1: 2. In Examples 12 and 13, the raw materials were blended so that the molar ratio of Na, Ba, Sr, Eu, Sc, and Si was 1: p: q: a: 1: 2. In Example 14, the raw materials were blended so that the molar ratio of Na, Ba, Ca, Eu, Sc and Si was 1: p: q: a: 1: 2. In Examples 15 to 18, the raw materials were blended so that the molar ratio of Na, Ba, Eu, Sc, Y, and Si was 1: (1-a): a: (1-z): z: 2. . In Examples 19-22, the raw materials were blended so that the molar ratio of Na, K, Ba, Eu, Sc and Si was (1-y): y: (1-a): a: 1: 2. In Examples 23 to 27, the raw materials were blended so that the molar ratio of Na, Li, Ba, Eu, Sc, and Si was (1-y): y: (1-a): a: 1: 2. In Examples 28 to 31, the raw materials were blended so that the molar ratio of Na, Ba, Eu, Mn, Sc, and Si was 1: (0.93-x): 0.07: x: 1: 2. In Examples 32-35, the molar ratio of Li, Na, Ba, Mn, Eu, Sc, and Si was 0.7: 0.3: (0.93-x): 0.07: x: 1: 2. The raw materials were blended so that

  Tables 2 and 3 show specific molar ratios of metal elements and values of a, p, q, y, and z in each example.

  This mixture was put into an alumina crucible and pre-baked by heating at 1100 ° C. for 12 hours in the air. By pulverizing the sintered body formed by this preliminary firing, the powder obtained thereby is put in an alumina crucible and heated at 1110 ° C. for 12 hours in a hydrogen / argon mixed gas atmosphere of 5% hydrogen concentration. This was fired. The sintered body formed by the main firing was pulverized to obtain phosphor particles.

[X-ray diffraction measurement]
Powder X-ray diffractometry using CuKα rays of the phosphor particles obtained in Examples 7 to 25 was performed. The results for Examples 7 to 11 are shown in FIG. 6, the results for Examples 12 and 13 are shown in FIG. 7, the results for Example 14 are shown in FIG. 8, the results for Examples 15 to 18 are shown in FIG. The results for Examples 19 to 22 are shown in FIG. 10, and the results for Examples 23 to 25 are shown in FIG. Further, for reference, FIGS. 7 to 11 also show diffraction intensity curves of NaBaScSi ₂ O ₇ obtained by simulation.

[Light emission characteristic evaluation]
Excitation spectra and emission spectra of the phosphor particles obtained in Examples 7 to 27 were measured. As a measuring device, a spectrofluorometer FP-6500 manufactured by JASCO Corporation was used.

  In measuring the emission spectrum, the wavelength of the excitation light was set to 450 nm. In the measurement of the excitation spectrum, the monitor wavelength was the wavelength at which the emission intensity of the emission spectrum was the maximum value in each example.

  As a result, in the phosphor particles obtained in any of the examples, the peak wavelength in the emission spectrum was around 500 nm, and the color of the fluorescence emitted from these phosphor particles was green. Furthermore, in the phosphor particles obtained in any of the examples, the waveform of the excitation spectrum is relatively flat from the near ultraviolet region to the blue region. Therefore, the excitation particles are excited in the near ultraviolet region to the blue region. It was confirmed that even if the wavelength of light fluctuates, the fluctuation of the emission intensity is small.

  FIG. 12 shows an emission spectrum (solid line) and an excitation spectrum (dashed line) for the phosphor particles obtained in Example 27. The emission intensity in FIG. 12 is a value (relative emission intensity) normalized by setting the emission intensity at the peak wavelength to 100.

  Table 4 and FIG. 13 below show the emission intensity at the emission peak wavelength in the emission spectrum for Examples 7 to 11. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  Table 5 below shows the emission intensity at the emission peak wavelength in the emission spectrum for Examples 7 and 12-14. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  Table 6 below and FIG. 14 show the emission intensity at the emission peak wavelength in the emission spectrum for Examples 7 and 15 to 18. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  Table 7 below and FIG. 15 show the emission intensity at the emission peak wavelength in the emission spectrum for Examples 7 and 19-22. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  FIG. 16 shows the emission intensity at the emission peak wavelength in the emission spectrum for Examples 7 and 23-25. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  Table 8 below shows the emission intensity at the emission peak wavelength in the emission spectrum for Examples 10, 26, and 27. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 10 to 100.

  Note that Example 9 has the same composition as Example 6, but the emission intensity is higher in Example 9. Since the measurement result of the emission intensity of Example 9 was highly reproducible, it is determined that the measurement result of Example 9 is more reliable.

  The emission spectra of the fluorescence emitted from the phosphors obtained in Examples 7 to 11 and Examples 28 to 35 were measured. As a measuring apparatus, a spectrofluorometer FP-6500 manufactured by JASCO Corporation was used, and the wavelength of excitation light applied to the phosphor was set to 450 nm.

  Moreover, the excitation spectra of the phosphors obtained in Examples 7 to 11 were also measured simultaneously using the above apparatus. The monitor wavelength was the peak wavelength in the emission spectrum of each phosphor. As a result, the waveform of the excitation spectrum of these phosphors is relatively flat from the near ultraviolet region to the blue region, and therefore emits light even when the wavelength of the excitation light varies in the near ultraviolet region to the blue region. It was confirmed that the intensity fluctuation was small.

  FIG. 17 shows an emission spectrum (solid line) and an excitation spectrum (dashed line) for the phosphor particles obtained in Examples 7-11. FIG. 18 shows the emission spectrum (solid line) and the excitation spectrum (broken line) for the phosphor particles obtained in Examples 28-31. FIG. 19 shows an emission spectrum (solid line) and an excitation spectrum (dashed line) for the phosphor particles obtained in Examples 32-35.

  According to these results, the peak wavelengths in the emission spectra of the phosphor particles obtained in Examples 7 to 11 and Examples 28 to 31 are around 500 nm and are emitted from these phosphor particles. The fluorescent color was green. Furthermore, the waveform of the excitation spectrum of these phosphor particles is relatively flat from the near ultraviolet region to the blue region, so that the wavelength of the excitation light varies in the near ultraviolet region to the blue region. Also, it was confirmed that the fluctuation of the emission intensity was small.

  Furthermore, in the emission spectra of the phosphor particles obtained in Examples 28 to 31, a relatively small peak was observed in the red wavelength region near 610 nm. Therefore, the use of the phosphors according to Examples 28 to 31 can be expected to improve the color rendering properties of the light emitting device.

  Table 9 below shows the emission intensity at the emission peak wavelength in the emission spectrum for the phosphors obtained in Examples 7 to 11 and Examples 28 to 35. The emission intensity is a value (relative emission intensity) normalized by setting the emission intensity value of the phosphor obtained in Example 7 to 100.

  Table 9 also shows the ratio of the intensity of the maximum peak in the red region to the intensity of the maximum peak in the green region in the emission spectrum for the phosphors obtained in Examples 28 to 35.

1 Light Emitting Device 70 Wavelength Conversion Member

Claims (16)

A phosphor having a chemical structure represented by the following general formula (A).
A (M _{1-a x} Eu _a Mn _x ) L (Si _1-b Ge _b ) ₂ O ₇ (A)
(A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, Y , La, Gd, and Lu, one or more elements selected from Lu, a is a number satisfying 0.001 ≦ a ≦ 0.3, b is a number satisfying 0 ≦ b ≦ 0.5, and x is 0 ≦ x It is a number satisfying ≦ 0.2.)   The phosphor according to claim 1, wherein x in the general formula (A) satisfies x = 0.   The phosphor according to claim 1, wherein x in the general formula (A) satisfies 0 <x ≦ 0.2.   The phosphor according to any one of claims 1 to 3, wherein Li is contained in A in the general formula (A).   The phosphor according to any one of claims 1 to 4, wherein Na is contained in A in the general formula (A).   The phosphor according to any one of claims 1 to 5, wherein A in the general formula (A) comprises at least two elements.   The phosphor according to any one of claims 1 to 6, wherein Ba in M in the general formula (A) is contained.   The phosphor according to claim 1, wherein M in the general formula (A) is composed of at least two elements.   The phosphor according to any one of claims 1 to 8, wherein Sc in L in the general formula (A) is contained.   The phosphor according to claim 9, wherein Y in L in the general formula (A) is further contained. The phosphor according to claim 1, 2 or 4, having a composition represented by the following general formula (2).
A ¹ _1-y A ² _y Ba _1-a Eu _a ScSi ₂ O ₇ (2)
(A ¹ and A ² are elements selected from Li, Na, and K, and A ¹ and A ² are different from each other. Y is a number that satisfies 0 <y <1, and a is 0. (The number satisfies 001 ≦ a ≦ 0.3.) The phosphor according to claim 1 or 2, having a composition represented by the following general formula (3).
NaBa _1-a Eu _a ScSi ₂ O ₇ (3)
(A is a number satisfying 0.001 ≦ a ≦ 0.3.) The phosphor according to claim 1 or 2, having a composition represented by the following general formula (4).
NaBa _1-a Eu _a Sc _1-z Y _z Si ₂ O ₇ (4)
(Z is a number that satisfies 0 <z <1, and a is a number that satisfies 0.001 ≦ a ≦ 0.3.) The phosphor according to claim 1 or 2, having a composition represented by the following general formula (5).
NaM ¹ _p M ² _q Eu _a ScSi ₂ O ₇ (5)
(M ¹ and M ² are elements selected from Mg, Ca, Sr, Ba, and Zn, and M ¹ and M ² are different from each other. A is a number that satisfies 0.001 ≦ a ≦ 0.3. P is a number that satisfies 0 <p <1, q is a number that satisfies 0 <q <1, and p, q, and a satisfy p + q + a = 1.) The phosphor according to claim 3, which has a composition represented by the following general formula (6).
A (M ³ _{1−a x} Eu _a Mn _x ) L (Si _1−b Ge _b ) ₂ O ₇ (6)
(A is one or more elements selected from Li, Na, and K, M is one or more elements selected from Mg, Ca, Sr, Ba, and Zn, and L is Ga, Al, Sc, Y , La, Gd, and Lu, one or more elements selected from the group consisting of: a: a number satisfying 0.001 ≦ a ≦ 0.3, b: a number satisfying 0 ≦ b ≦ 0.5, x: 0.01 ≦ x ≦ 0.2.)   16. A light emitting element that emits light having a main light emission peak in a range of 350 nm to 470 nm, and a wavelength conversion member that absorbs light emitted from the light emitting element and emits light, wherein the wavelength conversion member is any one of claims 1 to 15. A light emitting device comprising the phosphor according to claim 1.

Images